Exam 2 Pathology Flashcards
1
Q
Radicular pain
A
aka Root Pain
Lightning, stabbing, shooting pain in the dermatomal distribution of a dorsal root. Result of inflammation or extramedullary compression of a dorsal root.
2
Q
What is Transection/Transverse Myelopathy?
Describe the etiology (4) and general presentation (3)
A
Refers to a complete or nearly complete lesion encompassing the cross-sectional extent or breadth of the spinal cord at one, or a few adjacent, levels.
Etiology: Trauma, inflammation, compression, ischemia
Presentation:
- LMN signs localized to level of lesion
- UMN signs in limb muscles below level of lesion
- May present w/ septic shock
3
Q
Describe the etiology, pathophysiology and presentation of Syringomyelia
A
Pathophys: Cavity (syrinx) in central gray matter, which can expand.
Presentation: Initial vest-like spinothalamic sensory loss (pain/temp), w/ sacral sparing and sparing of positon sense/ vibration sense. Can have LMN signs if cavity disrupts anterior horn cells.
Etiology:
- Abnormal CSF flow/pressure due to Chiari malformations
- Tumor
- Residual from trauma
4
Q
Arnold-Chiari malformations
A
Downward displacement of the cerebellar tonsils through the foramen magnum (the opening at the base of the skull), sometimes causing non-communicating hydrocephalus as a result of obstruction of cerebrospinal fluid (CSF) outflow.
5
Q
Describe the presentation of Occlusion of the Anterior Spinal Artery
A
Sudden hyperreflexic, spastic paraparesis, loss of pain and temp below the lesion level.
Preserved vibration and position sense (intact dorsa columns).
6
Q
Describe the etiology (3), pathophysiology and presentation of Subacute Combined Degeneration of the Spinal Cord
A
aka Posterolateral Syndrome
Pathophys: Lesions in the posterior and lateral columns, usually at the thoracic level
Presentation: Loss of vibration and position sense in lower limbs (pain/temp preserved).
UMN signs (due to CST lesion) in lower limbs
Etiology: B12 deficiency* (most common), copper deficiency, HIV
7
Q
Describe the etiology, pathophysiology and presentation (3) of Tabes Dorsalis
What is also seen in conjunction with this disease?
A
Pathophys: Dorsal root lesions followed by subsequent dorsal column degeneration
Presentation:
- Initial lightning pain from root lesions
- Eventual loss of vibration, position sense and all sensory modalities of lower limb
- Areflexia and preserved strength
Etiology: Neurosyphilis
Can often see Charcot Joints
8
Q
What are Charcot Joints? What disease are they associated with?
A
Severe, traumatic injury and deformation of ankle joints due to loss of sensation from Tabes Dorsalis
9
Q
Describe the etiology (3), pathophysiology and presentation (3) of Brown-Sequard Syndrome
A
Pathophys: Spinal cord hemisection
Presentation:
- Contralateral STT deficit (loss of pain/temp)
- Ipsilateral CST deficit (muscle weakness)
- Ipsilateral Dorsal Column Deficit (vibration/position sense loss)
Etiology: Tumor (extramedullary); Trauma; Herniated disc
10
Q
Describe the presentation of Myasthenia Gravis
Age? Symptoms? Affect on sensations/reflexes?
A
- Begins at any age
- 10-20% how just ocular MG (ptosis, diplopia only)
- 80-90% show general MG (Possible weakness of all muscles)- Ptosis, diplopia, neck/limb weakness, respiratory weakness, etc.
- Preserved sensations/reflexes
11
Q
Pathogenesis of Myasthenia Gravis
A
- Antibodies to AchR which competetively block receptors and increase their degeneration and turnover
- Loss of this fxnal AchR leads allows even normal, mild reductions of Ach to lead to critical loss of end plate depolarization (and thus muscle fiber depolarization)
12
Q
Dx and Tx of Myasthenia Gravis
A
Dx:
- Tensilon Test (edrophonium)- AchE inhibitor
- Clinical presentation
- EMG evidence of abnormal NMJ transmission
- Elevated AchR serum antibody
Tx:
- Ach drugs (Usually AchE inhibitors)
- Thymectomy (Autoimmunity is likely initiated in the thymus due to AchR like molecules)
- Immunosuppresants
13
Q
Lambert-Eaton Syndrome
Presentation? Pathogenesis? What disease is it often associated with?
A
Pathogenesis: Autoimmune attacks against presynaptc calcium channels of the NMJ, leading to impaired Ach release.
Often arises as a paraneoplastic syndrome associated with Lung Small Cell Carcinoma
Presentation:
- Fatigable weakness of proximal limbs/trunk which mimics myopathy
- Weakness improves with use! (because there is more firing of nerves so more attempts at Ca2+ release so more antibody competition.
- Eyes are usually spared
14
Q
Dx and Tx of Lambart-Eaton Myasthenic Syndrome (LEMS)
A
Dx: nerve stimulation tests, EMG, specific antibodies
Tx: Resection of the cancer; drugs which enhance Ach release (guanidine; 3,4-diaminopyridine)
AchE drugs are NOT EFFECTIVE! - Ach is never released in the first place
15
Q
Mononeuropathy vs. Polyneuropathy
A
Mono: Injury to single, major, named nerve
Poly: Disorder of multiple, major and minor nerves (aka peripheral neuropathy)
16
Q
What are the (2) main causes of mononeuropathy?
How is “focal demyelination” related?
A
- Trauma
- Compression
Focal demyelination is seen in locations where the nerve is being consistently compressed. It may be accompanied by axonal damage if the lesion is severe.
17
Q
Describe the pathology of Carpal Tunnel Syndrome. How does it present (3)?
A
This is the most common mononeuropathy. It occurs when flexor tendons passing through the carpal tunnel get inflamed or swollen, compressing the median nerve.
Can also be caused by fluid retention in pregnancy.
Pt. presents w/ (1.) tingling/numbness in hand, (2) thenar weakness and (3) atrophy if severe.
18
Q
What is wallerian degeneration? How does it relate to axonal sprouting?
A
Results from traumatic mononeuropathy. When a nerve fiber is cut or crushed, the part of the axon separated from the neuron’s cell body degenerates distal to the injury.
If the framework /scaffolding remains, axonal sprouting may progress, allowing a new axon to grow to the appropriate muscle. Otherwise surgery will be indicated.
19
Q
What presentation is associated with polyneuropathy? (5)
A
- Stocking/glove sensory loss/impairment (feet first [longest sensory fibers], then hands)
- Paresthesia (spontaneous pins/needles)
- Dyesthesia (unpleasane sensation from a non-painful stimulus
- Distal limb weakeness/atrophy
- Declined reflexes
20
Q
What are the (2) general processes of polyneuropathy? What test is helpful in differentiating them and how do we read it?
A
- Demyelination
- Axonal Degeneration
EMG aka Nerve conduction studies are useful in reading stimulated sensory and motor neurons.
Dec. nerve conduction velocity = Demyelination
Dec. amplitude = Axonal Degeneration
21
Q
Pathophysiology of Guillain-Barre Syndrome.
Tx?
A
Pathophys- Inflammation and demyelination of peripheral nerves/roots (leading to ascending paralysis).
Tx: IVIG or plasmapheresis
22
Q
How common is chronic, acquired polyneuropathy?
What are the top (4) causes?
A
This is the most common neuropathy
DM, cancer, infxn, or nutritional
23
Q
What is the pathogenesis of hereditary neuropathy? Presentation? Tx?
A
Pathogenesis: Metabolic mechanisms or genetic disorders
Presentation:
- Childhood onset
- Distal sensorimotor deficits (little to no parasthesia/dysesthesia).
- Typically, orthopedic deformities are present (scoliosis, hammertoes, pes cavus aka high arch)
Tx: No curative treatment
24
Q
What is a myopathy? What are the general Sx? Dx?
A
It is a primary disease of the muscle
Sx:
- Weakness, fatigue, cramps
- Proximal limb weakness/atrophy (shoulders, hips, and thighs)
- Late reflex loss
- Intact sensation
Dx:
Elevated serum muscle enzymes, biopsy, EMG
25
What is _polymyositis_? What is the most common cause?
It is inflammation and weakness of multiple muscles
It can be the result of viral infx or drug rxn, but most often a result of **autoimmunity**.
26
What is the presentation of polymyositis (2)? Dx? Tx?
_Presentation_:
1. Proximal weakness over weeks/months
2. Rash (**dermatomyositis**) around eyes/fingers
_Dx_: EMG, **biopsy** showing inflammation/muscle fiber necrosis
_Tx_: Corticosteroids or other immunosuppressants
27
_Duchenne's Muscular Dystrophy_
How is it inherited? Pathophysiology? Presentation (including key signs)? Cause of death?
X-linked inheritance (so males only)
_Pathophys_: Loss of **dystrophin**- critical anchoring protein for muscle.
_Presentation_:
1. **Calf pseudohypertrophy** (replacment of muscle by fat)
2. Proximal weakness in young boys
3. Hip gyrtle weakness requiring _gower's sign_ to stand
4. **Cardiorespiratory death by 3rd decade**
28
_Spinal Muscular Atrophy_
Presentation/ Pathophysiology?
Infantile vs Childhood/Adult types?
Degradation involving anterior horn cells. Presents w/ LMN signs (weakness, atrophy, areflexia and fasiculations)
_Infantile_: **Werdnig-Hoffman Disease**- *terminal condition* due to rapid development of diffuse weakness, w/ no current curative treatment
_Childhood/Adult_: More mild; chronic disability
29
_Amyotrophic Lateral Sclerosis_
Pathophysiology? Tx? Prognosis?
Progressive degeneration of _all_ UMN and LMNs (so symptoms are both upper and lower)
_Tx_: **No cure**; Riluzole (glutamate antagonist) prolongs survival by months
_Prognosis_: Fatal (50% die w/in 3 years from resp. failure or complications of profound weakness)
30
Most common cause of damage to the olfactory nerve (CN I)
Sinusitis or URI
31
What reflexes contribute to the near reflex? (3)
Lens accomodation + pupillary constriction + convergence
32
When can we see a dissociation of the light reflex and the near reflex? How does the dissociation work? Give specific examples.
This is when the pupil constricts w/ the near reflex but not w/ the light reflex
It is due to selective disruption of the light reflex pathway at the pretectal area.
Occurs in **Neurosyphillis** (Argyll Robertson's pupil); **Dorsal Midbrain Lesions (ex. Pineal tumors****) --\>** _Parinaud's syndrome_ (if it also includes poor upgaze)
33
Pathophysiology for symmetrical vs asymmetrical nyastagmus
If lesions are present, where are they?
_Symmetrical (all directions of gaze):_ usually drugs/ metabolic
_Asymmetrical_: anatomical lesion
Lesions are in vestibular system, brainstem or cerebellum. Somewhere, where they are upsetting control/balance of eye movements.
34
What is internuclear ophthalmoplegia and what pathologies do we see it with?
Breaking of coordinated lateral gaze, due to problem w/ MLF. May also see nystagmus of abducting eye.
Seen w/...
1. MS in younger patient
2. Ischemic infarct of older patient
35
Trigeminal Neuralgia
What is it?
Who does it happen to?
Tx.?
* Short-circuiting nerve condition, causing lightning-jabs of pain (usually V2/V3).
* Seen in young MS patients
* Seen w/ tortuos blood vessels compressing nerve in older pts
* **Tx: Pain**
36
UMN lesion has what affect on the muscles of mastication? LMN weakness?
UMN Lesions: Due to bilateral control of muscles of mastication, UMN lesions may cause jaw weakness but no deviation.
LMN Lesions: Jaw-deviation is seen
37
Other than facial drooping, what are some other effects of seering CN VII? (2)
1. Loss of taste over ipsilateral anterior 2/3rds of tongue
2. Ipsilateral hyperacusis (sensitivity to loud sound) due to loss of stapedius branch
38
UMN vs LMN damage to tongue innervation
_UMN_: contralateral genioglossus *weakness* and tongue deviation to **opposite** side
_LMN_: Weakness to ipsilateral tongue, _atrophy_, _fibrillations_, and _fasiculations_ (you lick your wouds)
39
Weber Syndrome
1. What is it?
2. What causes it?
3. How does it present? (2)
1. It is a crossed brainstem syndrome of the _medial midbrain_
2. Caused by occlusion of the **posterior cerebral artery**
3. (1) *ipsilateral* CNIII damage; (2) *contralateral* hemiplegia (due to cerebral peduncle injury)
40
**Wallenberg Syndrome**
1. Also known as what?
2. What causes it?
3. Clinical manifestations? (5)
1. aka **Lateral Medullary Syndrome**
2. Caused by occlusion of PICA
3. **I PP** (on the) **NHL**:
* **I**psilateral unless otherwise noted
* **P**alatal/vocal weakness
* **P**ain/temp loss (_ipsi_: face; _contra_: body)
* **N**ystagmus
* **H**orner's
* **L**imb dysmetria
41
**Presentation**: Sudden onset, worst headache of life, some neurological deficit.
**Likely Dx:**?
Aneurysmal Subarachnoid Hemorrhage
42
**Presentation**: Pt. has consistent headache and has been previously diagnosed w/ a coagulopathy or is taking anticoagulants.
**Dx. to consider**: ?
_Dx_: Subdural or intradural hematoma
43
What drug class should you avoid for pt's w/ HA?
Give an example
Narcotics
Ex. **Butalbital-acetaminophen**
44
Are migraines usually unilateral or bilateral? When is the normal onset?
Unilateral
**Onset**: late childhood to early adult life (uncommon for first one in old age)
45
Name and describe the (4) Phases Migraines
1. **Prodrome**: 6-48 hours prior to headache; depression, irritabilit, drowsiness, hunger/thirst, rhinorrhea/lacrimation
2. **Aura**: usually visual; develop over 5-20 mins and lasts less than 60 mins; HA w/in 60 mins; due to spread of cortical depression
3. **Pain**: associated w/ photophobia/phonophobia; N/V; thermophobia/osmophobia
4. **Postdrome**: mood changes; impaired concentration; scalp/muscle tenderness
46
What is the basic path of effects that leads to migraine?
1. NMDA activation
2. Burst of focal cerebral activity
3. Wave front w/ depression behind it moving at 3mm/min
4. Trigeminal pathway triggered
5. Release of neuropeptides leading to symptoms
47
Tx. of Migraine
Treat early and often
1. NSAIDs (first line)
2. Triptans (second line)
48
All triptans are agonists of...
What are potential SEs?
5HT 1B/D receptors
SE of vasoconstriction
49
Serotonin syndrome
Potential SE for pt given a _triptan_ while on _antidepressants_
* Severe rigidity (mostly legs)
* Dysautonomia (inc. parasymp)
* Encephalopathy (myoclonos, hyperreflexia, and seizures)
* Usually w/in 24hr of med exposure
50
**Cluster Headaches**
1. Who do they affect?
2. Clinical presentation? (how often? for how long? uni or bi-lateral?)
3. Tx?
1. Men who are heavy smokers/drinkers
2. Clusters last 6-12 weeks, every 1-2 years; rapid onset of 1-4 attacks for 15-30 min period; unilateral (but can bounce between sides)
3. **O2, injectable sumatriptan**; nasal spray; lidocaine; DHE; prednisone
1. Oral drugs not of much use given rapid time
51
Phonophobia/Photophobiain a Tension HA
You can have one or the other, but not both at the same time
52
Trigeminal Neuralgia
1. What is it?
2. What is the usual cause?
3. Tx?
1. Paroxysmal pain attacks that last from seconds to minutes
2. Usually idiopathic, but **_MS_** is the most known cause **for young people**
3. Tx: Carbamazepine (1st line)
53
**Pseudotumor Cerebri**
1. Typical presentation?
2. Dx?
3. Tx?
4. Potential outcome?
1. Overweight, young, female, on oral contraceptives, and generalized headache
2. **Papiledema** on fundoscope; Spinal tap to confirm high intracranial pressure (\>250 mmH2O)
3. Tx. w/ acetazolamide, **topiramate**, or surgical intervention
4. Can lead to _blindness_ if not caught
54
Primary Exertional Headache
1. Presentation
2. Tx
1. **Presentation**: Young male w/ pulsating heading during/after physical activity
2. **Tx**: beta blockers; indomethacin
55
Charcot's Triad of MS
1. Nystagmus
2. Intention tremor
3. Scanning Speech
56
Stereotypical patient for MS
Younger (20-50), white, female from the north
57
Describe the pathogenesis for MS
1. APCs present neuronal tissue and prime **autoreactive T-cells**
2. T-cells attach to, break down, and cross **BBB**
3. T cells release interleukins causing inflammation; cytokines are released leading to myelin destruction
4. Axons usual _remyelinate_ but not well, eventually leading to axonal death and progessive degeneration
58
What are the (3) general syndromes which are highly suggestive of MS?
1. **Optic neuritis**
2. **Brainstem syndromes** (Including Internuclear Ophthalmoplegia -- essentially pathognomonic for MS)
3. **Spinal cord syndromes**
59
Describe the clinical manifestations of **Optic Neuritis** (associated syndrome of MS) (5)
1. Decreased monocular vision
2. Pain w/ eye movement
3. Decreased red/green color
4. Afferent pupillary defect
5. Heat intolerance
60
What is Lhermitte's "sign", and what is it associated with?
Lhermitte's "sign" is an _electric sensation felt by the patient when the neck is flexed_ ("sign" because it is actually a symptom). Associated spinal cord syndrome (which is suggestive of MS)
61
What is a key point about location of a plaque on MRI when it comes to MS?
In MS, plaques are found right against the pia surface
62
In MS cases, what does a black hole on T1 MRI tell us?
It is a sign of atrophy/ chronic damage
63
What is this image and what disease is it associated with?
Dawson's fingers
Pathognomonic for MS
64
What is the tract most commonly involved when there is an MS plaaque on the SC?
DSC
65
**Neuromyelitis Optica**
1. Pathophysiology
2. Associated symptoms
3. Dx
4. Prognosis
1. Longitudinal, extensive, spinal cord lesion (\>3 vertebral segments)
2. Bilateral optic neuritis. Hicups, and normal/minimal brain lesions
3. NMO IgG Ab positive
4. Much worse prognosis
66
Acute Disseminated Encephalomyelitis (ADEM)
1. What is this disease process associated with?
2. Presentation?
3. View on MRI
4. What patient population does this occur in?
1. Post-infectious process; differential for MS
2. One time process which commonly presents w/ HA, N/V, drowsiness and meningism
3. Large, fluffy, multifocal lesions
4. More common in children than adults
67
Progressive Multifocal Leukoencephalopathy (PML)
1. Pathology?
2. What conditions/virus is it associated with?
3. How is it related to MS?
4. How does it classically look on MRI?
5. How does it look on histology?
1. Multiple lesions frequently in subcortical hemispheric white matter or cerebellar peduncles
2. Associated with JC virus and the immunocompromised
3. Rare SE that occurs in those who are JC positive and on _natalizumab_, an MS drug
4. Hyperintense FLAIR signal in the right cerebellar peduncle is classic
5. **Histology shows**: loss of myelin (w/axonal sparing), bizarre astrocytes, ground glass oligodendroglial inclusions.
68
MS Tx
* **IV steroids are the preference** (_methylprednisonle_) or oral prednisone can be given
* ACTH, Plasmapharesis, IVIg
69
What is encephalitis ( and meningoencephalitis) and what is the usual cause?
Infxn of the brain parenchyma (w/ accompanying meningitis in the case of meningoencephalitis)
Mostly caused by _viruses_
70
Most common pathogens for acute bacterial meningitis for ages:
1-12 months
**: E. Coli, Group B Strep**
**1-12 months**: S. Pneumo, H. Flu (if unvaccinated)
71
Most common pathogens for acute bacterial meningitis for ages:
12 mo -16 y/o
16-50 y/o
Age extremes
**12 mo- 16 y/o:** N. meningitis, H. flu, S. pneumo
**16 - 50 y/o:** S. pneumo, N. meningitis
**Age extremes**: L. monocytogenes; Pseudomonas
72
Who is commonly affected by fungal meningitis?
The immunocompromised
73
Expected CSF findings for _Bacterial meningitis_:
1. Fluid quality?
2. Type of cells present?
3. Protein quantity?
4. Glucose levels (relative to plasma)?
5. Pressure?
1. Fluid quality? **Cloudy**
2. Type of cells present? **PMN's**
3. Protein quantity? **Very high**
4. Glucose levels (relative to plasma)? **Low**
5. Pressure? **High**
74
Expected CSF findings for _Viral Meningitis_:
1. Fluid quality?
2. Type of cells present?
3. Protein quantity?
4. Glucose levels (relative to plasma)?
1. Fluid quality? **Clear**
2. Type of cells present? **Lymphs**
3. Protein quantity **Slightly High**
4. Glucose levels (relative to plasma)? **Normal**
75
Expected CSF findings for _TB Meningitis_:
1. Type of cells present?
2. Protein quantity?
3. Glucose levels (relative to plasma)?
1. Type of cells present? **Lymphs**
2. Protein quantity? **Moderate**
3. Glucose levels (relative to plasma)? **Mildly Low**
76
Tx of bacterial meningitis
IV steroids + antibiotics
77
In TB meningitis, where is the exudate normally found?
The base of the brain
78
Expected CSF findings for _Fungal Meningitis_:
1. Type of cells present?
2. Protein quantity?
3. Glucose levels (relative to plasma)?
1. Type of cells present? **Lymphs**
2. Protein quantity **High**
3. Glucose levels (relative to plasma)? **Low**
79
(4) potential complications of bacterial meningitis
1. **H**ydrocephalus due to pus obstructing CSF outflow
2. **I**nfarction from thrombosis of inflamed superficial vessels of cortex/SC
3. **D**eafness in children
4. Secondary **E**dema and Inflammation of cortex (meingoencephalitis)
**HIDE** from meningitis
80
What are the (3) main types of parasitic infxns? Which is most common?
1. Cysticerosis (from Taenia Solium) \* most common
2. Toxoplasmosis
3. Amoebiasis ( N. fowleri, E. histolytica, etc.)
81
What are the key causes of _viral meningitis/encephalitis_ in the...
Summer/early fall?
Any season?
_Summer/early fall_- **Enteroviruses** \* and **arboviruses**\*\* (west nile)
_Any season_- **Herpes simplex virus**
\* most common cause
\*\* most common cause in USA
82
What are the (4) key microscopic findings in viral encephalitis?
1. Perivascular inflammation
2. Leptomenigeal inflammation
3. Microglial clusters (aka nodules)
4. Neuroplagia
83
Polioencephalitis
1. Transmission?
2. Pathogenesis?
3. Dx?
4. Similar to the pathology of what virus?
1. Fecal-oral transmission
2. Infxn and subsequent destruction of anterior horn cells (LMN)
3. Virus recovered from stool or throat
4. WNV
84
What is this image and what pathological process is it affliated with?
It is a **negri body** (cytoplasmic inclusion), seen in a neuron of the brainstem, cerebellum, or hippocampus.
Associated with **_Rabies_**
85
_Herpes Encephalitis_
1. Caused by what virus?
2. Transmission
3. Acute phase?
4. Chronic phase?
5. Sx?
6. Tx?
1. HSV-1
2. Transmitted via saliva
3. Acute- **Focal Encephalitis**- Bilateral but assymetrical edema, hemorrhage, and necrosis in the _temporal_ or _frontal_ lobes.
4. Chronic- "**burnt-out**" herpes-encephalitis
* Progression to cavitation and atrophy for long-term survivors
5. Sx: Aphasia, Behavorial changes, Memory impairment
6. Tx: w/ **acyclovir**
86
You see a "bullet-shaped" Rhabdovirus on EM. What disease do you suspect?
Rabies
87
What is this and what disease process is it associated with?
HSV-1 Intranuclear Inclusions (Owls-eye)
Herpes Encephalitis
88
What are the TORCH diseases?
TOxoplasma
Rubella
CMV
Herpes simplex
Can all be transmitted to the fetus
89
Congenital CMV Encephalitis vs CMV Postnatal infxn
_Congenital_: Moderately dilated ventricles and several foci of calcifications in the periventricular region. Lots of cytomegalic inclusions in all cellular elements of the brain
_Postnatal infxn_: numerous microglial nodules, only occasional cytomegalix cells with inclusions
90
HIV Encephalitis (HIVE) vs HIV Leukoencephalopathy
_HIVE_: Wide spread Multinucleated giant cells + microglial nodule (**pathognomonic for HIV encephalitis**)
_HIV leukoencephalopathy_: Subacute **HIVE** + onset of cognitive impairment and apathy (potentially leading to AIDS dementia).
91
What pathology is this image associated with?
Microglial nodule + multinucleated giant cell = HIVE
92
Vacuolar myelopathy
1. What is it?
2. What is it similar to?
3. Sx? (3)
1. Vacuoloation of the posterior and lateral spinal columns.
2. SImilar to Subacute Combined Degeneration seen in B12 def.
3. Spastic paraparesis + hyperreflexia + ataxia
93
Where are brain abscesses usually found?
In areas of the brain where the collateral circulation is the poorest (least blood flow).
94
Describe the Evolution of an Abscess
1. Initiating action
2. Days 1-3
3. Days 2-7
4. Days 5-14
5. 2 weeks +
1. Injury to micro-vasculature and spread of bacteria across the wall of the injured blood vessel
2. Early cerebritis
3. Confluent necrosis
4. Early encapsulation
5. Late encapsulation
95
What are the (2) main stages of Alcohol toxicity? Tx?
1. Early _hypersympathetic_ stage (tremors, sweating, tachycardia) and general seizures (12h to 3 days after withdrawal begins)
2. Delirium tremens w/ fluctuating motor and autonomic acitivity, confusion and hallucinations
**Tx**: Benzos
96
Name/describe the main chronic alcoholism syndromes (4)
1. **Wernicke's**- _TACO_: **T**hiamine deficiency; **A**MS; **C**erebellar dysfxn; **O**cculomotor Dysfunction
2. **Korsakoff**- amnesia, confabulation
3. Alcholic cerebellar degeneration
4. Peripheral neuropathy
97
Prion Disease
1. What is it?
2. Most common types?
3. Sx/Prognosis
1. Infxs proteins which induce conformational changes in normal proteins. Leads to neuronal death in the absence of inflammation.
2. Most common is **_Creutzfeldt-Jakob;_** Mad cow is next most common (bovine spongiform encephalopathy)
3. _Sx_: dementia w/ myoclonus (often corticospinal) _Prognosis_: Rapidly progessive, untreatable, fatal
98
Optic atrophy
1. Occurs when?
2. What does the optic disc look like?
3. What is it result of?
1. Occurs weeks after an optic nerve lesion
2. Pale optic disc w/ sharp, distinct images
3. Result of destruction of retinal ganglion cell axons (not an occiptal lesion)
99
_Pituitary Lesion_
Describe the pathology and clinical presentation
This tumor compresses the center of the optic chiasm from below, taking out superior vision loss and the eventually will cause bitemporal hemiopsia.
100
Major effect of occlusion of the PCA
Cortical blindness due to bilateral occipital infarcts
101
Conductive deafness and Nerve deafness
Which is high tone? Which is low tone?
**Conductive deafness**: low tone (impacted wax; ossicle lesion)
**Nerve deafness**: high tone
102
Benign Positional Vertigo
1. Common in who?
2. Pathology?
1. Elderly
2. Degenerated otoliths w/ Ca2+ crystals lodged over cilia so minor movements of head creates vertigo sensations
103
Acute labyrinths
Viral infxn or inflammation of inner ear labyrinth which leads to asymmetrical nystagmus, unilateral hearing loss, and gait ataxia on exam
104
Meneire's disease
Membranous labyrinth swells/ruptures
Intermixed endo- and peri-lymph impairs receptors
Permanent deafness may occur after repeated bouts
_RARE_
105
Put these cells in order of most to least sensitivity to ischemia
oligodendrocytes, astrocytes, neurons, endothelial cells
1. neurons
2. oligodendrocytes
3. endothelial cells
4. astrocytes
106
What are the (4) major etiologies of Global ischemia?
1. Low perfusion
2. Acute drop in BF
3. Chronic hypoxia (anemia)
4. **Repeated episodes of hypoglycemia (insulinoma)**
107
Histological changes in first 6-12 hours after an infarct
Red Dead Neurons
1. Cytoplasmic eosinophilia
2. Loss of Nissl substance
3. Dark pyknotic nuclei1
108
Key watershed areas for brain infarcts (3) in adults
In children?
**Adults**:
1. Pyrimadal neurons in cerebral cortex (Laminar necrosis)
2. Pyrimadalneurons in hippocampus
3. Purkinje cells of cerebellum
**Infants**:
Thalamus and Pons
109
A dominant hemisphere MCA infarct is often associated with...?
A non-dominant?
_Dominant_: Expressive aphasia
_Non-dominant_: Neglect
110
Are lacunar infarcts are usually the result of embolisms or in-situ thrombosis?
In-situ
111
General Etiologies for hemorrhage above the arachnoid? Below?
_Above_: Trauma
_Below_: Underlying cerebrovascular disease (Subarachnoid - Berry Aneurysm) or (Parenchyma- HTN)
112
Top (2) locations for Berry Aneurysms
1. ACA
2. MCA
113
Most common cause for subarachnoid hemorrhage? Second most common cause?
1. Trauma
2. Berry-aneurysm
114
Intraventricular Hemorrhage is most common in who? Most common where?
1. Common in premies
2. Germinal matrix (beneath the ependyma)
115
Duret Hemorrhages are caused by...?
Secondary compression from herniation of the medial temporal lobe, leading to stretching and ischemia of perforating arterioles
116
Most artery involved in epidural hemorrhage? Most common mechanism of injury?
Talk and die or progressive?
Classically due to a temporal bone fracture w/ rupture of the middle menigeal artery
(MMA fighters have epidural bleeds)
Talk and die
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Subdural Hematoma
Talk and die or progressive? What vessels are the usual cause?
Progessive decompensation
Usually casued by bridging veins rupture
118
Describe the (3) main herniation types and their potential consequences
1. _Tonsilar_: Displacement of cerebellar tonsils into foramen magnum; Compression of brainstem and subsequent Cardiopulmonary arrest
2. _Subfalcine_: Displacement of cingulate gyrus under falx cerebri; Compression of ACA leading to infarction
3. _Uncal_: Displacement of medial temporal lobe under tentorium cerebri; **POP**: **_P_**aramedian vessel rupture (duret), **_O_**culomotor compression, **_P_**CA compression
119
ARAS
Ascending reticular activating system
120
When testing a patient in a coma, what does the following sign suggests?
- Withdrawal from painful stimuli
Some remaining cortical function
121
When testing a patient in a coma, what does the following sign suggests?
(Reflexive movement to pain test)
_Decorticate posturing_
_Decerebrate posturing_
**Decorticate**- Cerebral hemisphere lesion
**Decerebrate**-Lesion in midbrain (red nucleus)
122
When testing a patient in a coma, what does the following sign suggests?
(Breathing patterns)
Cheyne-stokes
Ataxic, irregular respiration
_Cheyne-Stokes_: due to bilateral cortical lesions
_Ataxic-irregular_: lesion near respiratory center (impending resp. failure)
123
When testing a patient in a coma, what does the following sign suggests?
Pupillary light reflex
Brainstem is intact at least at level of midbrain
124
When testing a patient in a coma, what does the following sign suggests?
Oculocephalic reflex
Oculovestibular reflex
Occulocephalic (doll's eye): intact brainstem
Oculovestibular (ice water in ear canal- eyes move towards cold water): intact brainstem
125
After checking for ABC's, what is my next critical step for tx. of a coma patient in an emergent situation?
Immediately check hypoglycemia or give 50% IV dextrose
126
How long most cerebral blood flow be abscent to qualify a patient as having brain death?
Absent cerebral blood flow over 10 mins
127
What is the etiology of hemiballismus?
Lesion of the Subthalamic Nucleus (STN), which normally stimulates the GPm
128
Primary and secondary clinical of parkinsons
PARK HAM
_Primary_: **P**ill rolling tremor, **A**reflexia postural reflexes, **R**igidity, **K**inesia(brady)
_Secondary_: **H**ypophonic speech, **A**utonomic dysfxn, **M**icrographia
129
What is the relationship between CO poisoning/ manganese poisoning and parkisons disease
Poisoning from these substances can lead to _parkisonism_
130
Clinical Dx of Parkinson's disease (4)
1. \> or equal to 2 primary clinical signs
2. 40-70 y/o
3. Exclusion of other causes
4. Initial signficant improvement w/ dopaminergics
131
What are Lewy bodies and how are they related to Parkinson's?
They are eosinophilic, intraneuronal cytoplasmic inclusions which are an accumulation of **_a-synuclein_** (synucleinopathy).
Seen in _advanced_ parkinson's. Some families have a-synuclein and/or parkin mutations increasing susceptibility to parkinson's.
132
Parkinson's Tx (3)
1. L-Dopa (+ Carbidopa)
2. Pallidotomy (destruction of GPm)
3. STN stimulator (actually serves to inhibit STN and thus inhibits GPm)
133
What does the CT show for Huntington's patients?
Atrophy of caudate nuclei and cerebral cortex
134
What is the genetic abnormality for Huntington's disease? (including the chromosome which is abnormal)
_Trinucleotide_ repeats of Huntington gene at **chromosome 4** (\>35 _CAG_ repeats)
135
What are the early onset genetic changes for Alzheimer's? Late onset? Protective?
_Early_: Down's Syndrome, Presenilin 1/2 (chromosome 14/1)
_Late_: ApoE4
_Protective_: ApoE2
136
Alzheimer's and Amyloid
Abnormal cleavage of Amyloid precursor proteins leads to excess accumulation of amyloid.
137
Where are the earliest signs of Alzheimer's often seen in the anatomy?
Hippocampus
138
Neurofibrillary Tangles (NFT)
(what are they? what kind of proteins? what does it correlate with?)
* Intracellular filamentous inclusions
* Hyperphosphorylated _tau_ protein
* Density correlates w/ degree of dementia
139
Amyloid angiopathy
Amyloid deposition in walls of arterial vessels in subarachnoid space, that separates media and adventitia. Present in almost all AD cases
140
What are the top (3) causes of dementia?
1. Alzheimer's
2. Lewy Body Disease
3. Frontotemporal Lobar Degeneration (Of which Pick's disease is a subset)
141
_Lewy Body Disease_
Describe the Pathophys and the Sx's
1. Lewy bodies composed of _a-synuclein_ in cortex and brainstem
2. Initial dementia and visual hallucinations followed by parkinsonian symptoms
142
_Frontotemporal Lobar Degeneration_
1. Pathophys? (key chromosome involved?)
2. Presentation?
3. Key disease under this umbrella
1. Mutations in tau protein gene in _chromosome 17_ leading to breakdown of the frontal and temporal lobes
2. Changes in personal and social conduct
3. **Pick's disease** is a subset
143
_Pick's Disease_
1. What is this disease a subset of?
2. Presentation?
3. What are Pick's Bodies, what are they composed of, and where are they found?
1. Rare type of **frontotemperal** dementia
2. **Aphasia** (w/ minimal memory loss); can lead to dementia
3. _Pick's Bodies_- Globose neuronal cytoplasmic inclusions composed of **tau** and found in the *hippocampus and cortex*
144
What are the systems affected in multisystem atrophy? What is the pathology?
1. _COPS_: Cerebellum (leading to ataxia), Olivary and Pons (leading to autonomic dysfunction), Substantia Nigra (leading to Parkinsonism)
2. Glial Lewy bodies
145
What is the genetic mutation associated with familial ALS?
Mutation on the gene for Superoxide Dismutase (SOD1)
146
Werdnig-Hoffman Disease
1. Mode of inheritance
2. Pathology
3. Presentation
1. Autosomal recessive _SMAI defect_ on **Chromosome 5**
2. Degeneration of LMNs and atrophy of distal muscles
3. "Floppy baby syndrome" (affects fetus/neonate)
(sick before they can say their first "werd")
147
Kugelberg-Walander Disease
1. Key genetic mutation
2. Similar to what disease?
3. Prognosis?
1. _SMA II_ mutation at chromosome 5
2. Similar to Werdnig-Hoffmann but presents after 3mo
3. Chronic -- compatible with normal life span
148
_Freidrich's Ataxia_
1. Most common form of...?
2. Describe the genetic issue
3. What neural components are degenerated?
1. Most common hereditary ataxia
2. Trinucleotide repeat of GAA at chromosome 9
3. freidri**CH'S******
* **C**erebellum (ataxia)
* **H**eart (electrical conduction and structural anomalies)
* **S**pinal (vibration loss)
149
_Vascular Dementia_
1. This is ultimately just a product of what?
2. What other dementia process is this closely associated with?
3. What genetic changes can be associate?
4. What is the most common genetic form of this disease and what arteries does it involve?
1. **Loss of blood flow to tissues** (could be ischemic infarcts, hemorrhagic infarcts, hypoperfusion, amyloidosis leading to hemorrhage, etc.)
2. Associated w/ _mixed dementia_ (Alzheimer's disease + vascular dementia)
3. ApoE4 increases risk.
4. CADASIL is most common genetic form, involving small vessels
150
What effect does Wenicke's encephalopathy have on mamillary bodies? (Acutely? Chronically?)
**Acute**: Mammillary body w/ petechial hemorrhages
**Chronic**: shrunken mamillary bodies
151
Methanol toxicity vs CO poisoning
1. MOA for methanol toxicity
2. Type of injury seen in each
3. Location of injury for each
1. _Methanol_: Liver oxidation of methanol to formaldehyde and formic acid
2. Hypoxic injury w/ white matter necrosis/ hemorrhage
3. _Methanol_: Affects putamen and claustrem; _CO_: bilateral globus pallidus
152
Central Pontine Myelinosis is caused by
Triangular lesion w/ myelin loss due to rapid correction of electrolyte imbalance for alcoholics
153
Name the most common Primary Brain Tumors for an Adult.
Child?
_Adult_: (Gates Miliennium Scholar) **G**lioblastoma, **M**eningioma, **S**chwannoma
_Child_: Med-PEds
**Med**ulloblastoma, **P**ilocytic astrocytoma, **E**pendymoma
154
Grades for Astrocytoma and key tumors associated (4)
_Grade I_: Least malignant, slow growing, possible to cure w/ resection. **Juvenile Pilocytic Astrocytoma**
_Grade II_: Infiltrative/ recurrent, but no mitosis, necrosis, or angiogenesis
_Grade III_: Malignant but no microvascular proliferation/ necrosis (give radiation/ chemo)
_Grade IV_: Most malignant CNS tumor type. Fatal outcome. **Glioblastoma**
155
Key histological presentation _Juvenile Pilocytic Astrocytoma_
1. Cell type?
2. Architecture?
3. Type of fibers?
4. Classic finding on MRI?
1. _Piloid_ cells w/ hair like processes
2. Biphasic architecture (compact and microcytic areas)
3. _Rosenthal fibers_
4. On MRI - _Cyst_ w/ mural nodule
156
Tumor marker for _Glioblastoma_
(+) GFAP
157
1. What primary brain cancer does this image pertain to?
2. Normal location for this cancer?
3. Describe the expected Histo
1. Oligodendroglioma (intratumoral calcifications on CT)
2. Usually frontal lobe
3. **Fried-egg appearance** (perinuclear halos); **Chicken-wire** capillary pattern
158
In a rosette, what type of cancer has a core of...
1. Neuropil fibrils (homer-wright)
2. Empty lumen
3. Blood vessels
4. Empty central sulcus
1. Medullablastoma
2. Retinoblastoma
3. Ependymoma (pseudorosette)
4. Ependymoma (true rosette)
159
Where is an Ependymoma most common?
They arise from the ventricle walls/ central canal of the SC. **4th ventricle** is the most common site
160
1. What cancer is this image associated with?
2. What type of cells does it arise from/ where in the brain?
3. How does it spread?
1. Medullablastoma
2. Arises from _undifferentiated neuroectodermal_ cells in the **cerebellum** of kids; **cerebrum** (hemispheric) of adults.
3. Spreads along CSF pathways (so can be seen discretely on an MRI)
161
Whorls, Psammoma bodies, Fasicles and a Dural tail, are all associated with what cancer? What specific cell type does this cancer grow from?
Meningioma
| (Arachnoid layer)
162
1. What cancer is this image associated with?
2. What population is most commonly affected?
3. What is this often confused with?
4. What embryological pouch does this develop from?
1. Craniopharyngioma
2. Children
3. Pituitary adenoma
4. Rathke's pouch
163
**Schwannoma**
1. Where does this most commonly occur/what happens?
2. What (2) related processes lead to it?
3. What does it stain with?
1. Cerebellopontine angle (where cranial nerve VIII runs). Leads to **acoustic neuroma**.
2. Neurofibromatous Type 1 and Type 2
3. Stains for S100 protein
164
What gene is involved w/ NF1? NF2?
1. NF1: 17q11.2
2. NF2: 22q12
165
What is this and what disease is this pathognomonic for? How does it look on gross.
**Plexiform neurofibroma**: tumor involving multiple nerve fasicles. Looks like _bag of worms_ on gross
(seen in NF1)
166
What (2) genes are associated w/ tuberous sclerosis?
1. TSC1 (9q) - hamartin
2. TSC2 (16p)- tuberin
167
Classic triad for Tuberous Sclerosis
Other key presentations and important
1. Seizures
2. Adenoma sebaceum
3. Mental retardation
**SAM** had Tuberous Sclerosis
Involves Tubers (even on face) and SEGAs (subependymal giant cells which can lead to hydrocephalous)
168
What disease is this image associated w/? Explain. What chromosome is affected?
VHL disease (loss of tumor suppressor on chromosome 3)
CNS Hemangioblastoma (closely arranged thin-walled capillaries which can rupture)
169
Tabetic gait
| (what is it? what causes it?)
**Foot slapping gait**, where patient compensates for impaired sensation by forcibly planting foot down.
Due to neurosyphilis or severe neuropathy
170
Waddling gait
| (what is it? what causes it?)
When walking, weak pelvic/hip muscles cannot support the body "on one leg", so patient compensates.
Usually the result of a _myopathy_
171
Scissors gait
| (what is it? what causes it?)
Weak legs but have spasms in adductor muscles forcing the knees stiffly together when walking
Due to CST lesion
172
Festination
Leaning further and further to walk (Parkinson's)
173
Kinetic tremor vs Dysmetria
_Kinetic_: rhythmic oscillations during limb movement towards a target
_Dysmetria_: Overshooting or undershooting a target
174
Dystonia vs myoclonus
_Dystonia_: Frequent, constant contraction
_Myoclonus_: Shock-like jerking or twitches
175
1. Where would a lesion be that causes Wernicke's aphasia?
2. Broca's?
3. What additional sign would expect?
1. _Wernicke's_: Posterior, superior temporal
2. _Broca's_ Posterior, inferior frontal
3. **Hemiparesis** would also be expected in damage to these areas because of proximity to motor cortex. (no hemi? suggests psychosis/drug use)
176
Where would a lesion be that causes conductive aphasia?
How does it present?
**Arcuate fasiculus** (tract between Broca's and Wernicke's)
Intermediate versions of both (particuarly Wernicke's)
177
1. What deficits would a posterior, _D__ominant hemisphere lesion_ lead to?
2. _Non-dominant hemisphere lesion_?
1. _Dominant_: alexia (impaired reading); agraphia (impaired writing)
2. _Non-dom_: aprosodies (semantic understanding)
178
Lesions at what (3) locations lead to memory issues?
1. Hippocampus
2. Mamillary bodies
3. Thalamus
179
Where would a lesion be to cause gait apraxia? constructional or dressing apraxia?
_Gait_: prefrontal/frontal
_Construction/dressing_: Parietal
180
Agnesia
| (what is it? what causes it?)
* _Impaired recognition_ of perceived stimuli via one sensory modality (ex. can see it and not recognize, but hear it and know)
* Due to lesion in sensory association cortex
181
What is paratonia?
In what syndrome do you see both Paratonia and frontal lobe release signs?
1. Frontal lobe release signs (normally seen in infancy)
2. _Paratonia_: Resistance to rapid passive movement of a limb. Seen in frontal lobe syndrome
## Footnote
**Frontal Lobe Syndrome**
182
Kluver-Bucy is caused by what lesion type?
Bi-temporal
183
Parietal Lobe's main functioning?
Sensory
184
Anton's Syndrome?
Prosopagnosia?
Both are the result of what?
_Anton's_: Denial or unawareness of cortical blindness
_Prosopagnosia_: Inability to recognize previously known faces
Both are the result of bilateral occipital lesions
185
Name the (3) types of partial seizures
1. Simple Partial (focal w/o LOC)
2. Complex Partial (focal + LOC)
3. Partial + secondary generalized (focal then generalized)
186
1. Most common partial seizure
2. What are the preceeding symptoms?
3. What does the seizure look like?
1. Temporal Lobe
2. _Epigastric Aura_ (rising sensation, fear, deja vu, olfactory, and gustatory sensations)
3. Staring, unresponsiveness, oroalimentry, and gestural automatisms
187
Frontal Lobe Seizures
1. Timing?
2. Types of movements (2)?
3. Focal seizure patterns (2)?
1. Usually at night
2. Complex movement + Versive movements (head/eye rolling to opposite side of seizure)
3. Focal seizure w/ Jacksonian March (through homonchulous) + Post-ictal "Todd's" Paralysis
188
Tx. of Absence seizures
Ethosuximide
189
1. What is a myoclonic seizure?
2. When does it happen?
3. Tx.?
1. Fast, shock-like contraction
2. Early in the morning for teenagers (often after alcohol use/ sleep deprivation)
3. Tx. **Valproic acid**
190
Tonic vs Clonic
* _Tonic_- contraction producing extension/arching
* _Clonic_- Alternating contraction/relaxation
191
If you wanted to treat a child with febrile seizures (although you don't need to).
Rectal Diazpam
192
Status Epilepticus
1. What is it?
2. Treatment?
1. **NEUROLOGICAL EMERGENCY**
* Continuous seizures (\> 5min, neural death \> 30 min)
* Greater than (2) seizures in a row w/o regaining of conciousness
2. Tx:
* Glucose check (consider thiamine)
* Lorazepam
* Phenytoin
* ICU admission (Propofal or IV medazlin)
